Cold-spray materials/coatings exhibit several advantages associated with the solid-state character of the deposition process. Although processing effects on particle bonding and static properties of these materials have been studied, very little is known about the influence of processing parameters and resulting microstructures on fatigue crack growth (FCG) and the coating-substrate interfacial mechanisms. In this work, systematic FCG studies were conducted on cold-spray processed 6061 freestanding parts and coatings for various processing conditions (as cold-sprayed, annealed, T6). Room temperature tests were performed at three stress ratios (R=0.1,0.5,0.7). Long and small FCG mechanisms at the microstructural scale of cold-spray materials were identified, and a microstructure-based model was successfully developed to predict FCG rates in Regions II and III. The interfacial behavior between the cold-spray coating and the wrought 6061 substrate was uniquely examined, and crack-interface stability maps were created. These developments will be presented and discussed for component design and coatings/repairs.

Proceedings Inclusion?

Planned: Publication Outside of TMS (Indicate publication title and publisher if known.)